Deformable mirrors are used in optical applications to reshape optical wave fronts, for example to compensate for atmospheric turbulence. For this purpose it is necessary to impose and/or constrain deformations of a reflective surface with high spatial frequencies.
In order to impose and control these deformations an array of actuators is used. It should be possible to exert accurate control over the displacements of the different regions with a high bandwidth independently in small regions that together cover over a large surface. Current deformable mirrors have unsatisfactory bandwidth, resolution and size. It is often impossible to control displacement with sufficient accuracy.
For satisfactory use it may also be necessary to place further demands on the capability of deforming the surface, for example regarding speed, maximum possible amplitude of the deformations (e.g. of a point deformation), low coupling between actuators, high density, scalability, low friction, hysteresis and play, high reproducibility etc. Similar demands may be placed on actuator structures for deforming surface in general, not only for reflective surfaces.